Taxonomic notes

This species was described as a member of Echinodontium, but Tabata et al. (2000) revealed that this is not related with E. tinctorium, the type species of Echinodontium. It should be a member of Russulales, but the adequate genus for this fungus is still unclear, yet.

Why suggested for a Global Red List Assessment?

Grows on branches of evergreen oaks usually of Quercus sessilifolia in restricted old growth forests. In literature, also reported from Quercus gilva and Q. glauca, but it is yet to be confirmed.

The species was described in 1935, but only based on about 10 specimens hitherto known from about 5 localities in Japan. In addition, a record from India was cited by Imazeki and Hongo (1989), but few information is available for the Indian population.
Two records have been made from Kasuga-yama Hill (Nara Pref.), the type locality, in 1935 and 1976, but no further records has been made since then. Kasuga-yama covers an area of about 2.5 km2, and consists of an isolated ‘virgin’ evergreen oak forest, maintained for religious reasons. Was also recorded from evergreen oak forests in the southwestern area of Miyazaki Pref. in Japan. Four localities have been confirmed after 2000 in Miyazaki, but one site was already lost because of a dam construction. Possible localities in Miyazaki cover an area of about 30 km2.

Red List of Threatened Species of Japan (2012): CR+EN

Geographic range

Known from 2 warm temperate locations (Nara and Miyazaki) in Japan, and Himadral Pradesh, India (Imazeki and Hongo 1989). It was also recorded from Shimla-Mahasu and Chamba-Dalhausie, India (Prasher and Ashok, 2013), but these records are dubious because of the occurrence on conifer trees. Two locations in Japan are ca. 400 km apart, and isolated.
Despite very intensive collections of polypores and other aphyllophoraceous fungi in Continental China, Taiwan and Japan in recent 20 years, no further localities has been found in other areas of East Asia.

Population and Trends

2 records have been made from Kasuga-yama Hill (Nara Pref.), the type locality, each one collection on 1935 and 1976, but no further record has been made since then for more than 30 years. 1 collection on 1938, and 5 collections from 4 localities have been made after 2000 (2003, 2004, 2006 and 2014) in Miyazaki, but 1 locality site was already lost because of a dam construction. Detailed records are as follows:
Nara Pref., Kasuga-yama (1935, 1976; no further record)
Miyazaki Pref., Suki (1938; no further record); Kobayashi 1(2003; locality already lost), Kobayashi 2 (2005); Kobayashi 3 (2006); Aya (2014). A single host tree is known for each locality.

Population Trend: Decreasing

Habitat and Ecology

The two known localities are old-growth forests consisted by Querus sessilifolia, Q. gilva and other evergreen trees located in warm temperate areas of Japan. All of recent collections in Miyazaki were made on dead branches attached with living trees and/or trunks of Quercus sessilifolia, and this should be the most important host tree species. This is an evergreen oak tree distributed in Japan and Taiwan, but sparse in many of the distribution areas. It prefers wet condition, and often seen along or near rivers and streams. On literature, this fungus was also recorded on Quercus gilva and Q. glauca, both are evergreen oaks, but can be dubious.
Sporocarps of this fungus is annual-short perennial, but mycelial may persist in the substrates for several years.

Temperate Forest

Threats

Huge oak trees are declining by the spread of the oak wilt disease caused by a bark beetle (Platypus quercivorus) and Raffaelea quercivora in both of Nara and Miyazaki, and it can be a serious threat for this fungus.
One locality in Miyazaki was already lost by a dam construction. Quercus sessilifolia, the host tree species, is often distributed along streams and rivers, and dam construction can be a serious threat for this fungus.
Most other possible habitats for this fungus had been likely already destroyed by deforestation in other areas of Japan.

Unintentional effects: large scale (species being assessed is not the target) [harvest]Dams & water management/useNamed species

Conservation Actions

Conservation of evergreen oak forests mixed with Q. sessilifolia in southwestern areas of Miyazaki and surrounding areas in Kyushu Island is desirable. The oak wilt disease in and around Nara and Miyazaki should be controlled.

Site/area protectionResource & habitat protection

Research needed

Intensive surveys are desirable to monitor occurrence of this fungus both in the type locality (Kasuga-yama) and Miyazaki to reveal its distribution and detailed habitat condition. This is morphologically a distinct species, but can be overlooked because of the almost resupinate sporocarp. It is also desirable to conform it status in India.